Download Heat transfer - hrsbstaff.ednet.ns.ca

Heat Transfer and Solar Radiation
Consider This:
 You are spending the day at the beach. You are lying
on your towel. You feel the soothing warmth on your
skin. A breeze wafts by and you feel cool, momentarily.
The sun continues to beat down on you and you start to
feel uncomfortably warm. You stand up and walk towards
the water. The sand is hot and feels like it is burning the
bottom of you feet. You step into the water. It feels
chilly, but you quickly adapt and enjoy the swim. When
you get out of the water, the air feels cool and you start
to shiver. You grab your towel, dry off, and lay in the sun
again, feeling comfortable.
 How is solar energy interacting with air, land, and water?
Heat
 Thermal energy transferred from one object to
another.
 Goes from high to low thermal energy.
 hot to cold
 The Heating Song
Heat Transfer
Conduction:
 Heat transfers by collisions between particles.
 Usually between solids.
Heat Transfer
Convection:
 Heat transfers by high energy particles moving and
rising.
 Usually with liquids and gases.
 Hot particles rise (less dense)
 Cold particles fall (more dense)
 This creates convection currents.
Heat Transfer
Radiation:
 Heat transfer through electromagnetic waves.
 Waves transport energy
through space.
 They release it when they
interact with something.
Consider This:
 Think back to the beach scenario:
 When did radiation take place?
 When did conduction take place?
 When did convection take place?
Consider This:
 Think back to the beach scenario:
 When did radiation take place?
 Heat from sun reaches your skin.
 When did conduction take place?
 Hot sand on your feet.
 When did convection take place?
 Water is warmer at the surface.
Solar Radiation
 The primary source of heat for soil and water.
 Helps drive all weather systems!
 When it enters the atmosphere:
 Some is reflected back to space.
 The rest is absorbed by the atmosphere or Earth’s
surface.
Earth’s Energy Budget
 This helps maintain Earth’s constant temperature.